Mandrel with variable pocket widths for automatic packaging machines

Abstract

An automatic packaging machine has mandrels with a plurality of fingers for gripping an object. A cam track has contours which defines the location of positions along a conveyor carrying the mandrels. The fingers are closed by a spring and opened by a cam follower encountering a contour of cam track. This way a plurality of objects having a variety of widths may be carried by the fingers without requiring a readjustment of the machine.

The claimed invention is:  
     
       1. In an automatic packaging machine, a mandrel comprising a support plate having at least two pairs of elongated tracks, said pairs of elongated tracks being oppositely disposed, said elongated tracks of each pair being vertically aligned, a finger mounted to travel on each of said elongated tracks of said support plate, a cam follower means for traveling in a cam track extending along a conveyor in said automatic packaging means, said cam track having contours which guide and direct said cam follower as a function of an instantaneous position of said mandrel as it travels along said conveyor, means responsive to said cam follower for moving said fingers on said tracks, and spring means for pulling said fingers to grip an object between said fingers, movement of said cam follower means along said contours opening said grip and said spring means closing said grip, wherein said object is a box and each of said fingers has a circumferential groove located to grip and squeeze opposite edges of a blank for forming said box, said blank expanding to form an oddly non-parallelepiped shaped box responsive to said squeeze. 
     
     
       2. The mandrel of  claim 1  wherein said oddly non-parallelepiped shaped box is a barrel-shaped box. 
     
     
       3. In an automatic packaging machine, a mandrel comprising a support plate having at least two pairs of elongated tracks, said pairs of elongated tracks being oppositely disposed, said elongated tracks of each pair being vertically aligned, a finger mounted to travel on each of said tracks of said support plate, a cam follower means for traveling in a cam track extending along a conveyor in said automatic packaging means, said cam track having contours which guide and direct said cam follower as a function of an instantaneous position of said mandrel as it travels along said conveyor, means responsive to said cam follower for moving said fingers on said tracks, and spring means for pulling said fingers to grip an object between said fingers, movement of said cam follower means along said contours opening said grip and said spring means closing said grip, a freely turning pulley wheel mounted on said mandrel, said spring means being a coiled spring stretched over said pulley wheel responsive to said travel of said cam follower, and means responsive to the tension of said spring stretched over said pulley wheel for closing said grip. 
     
     
       4. An automatic packaging machine comprising a conveyor for moving a plurality of object carrying mandrels around a closed path, a cam track accompanying said path, said cam track having contours which define functional locations along said path, each of said mandrels having a plurality of fingers which move variable distances together or apart in order to grip or release one of a plurality of objects having different widths, means responsive to said contours of said cam track for causing said fingers to release said object, spring means for causing said fingers to grip said object, whereby objects of different widths are selectively carried by said mandrels without requiring a readjustment of said machine, and at least one work station located adjacent said conveyor, said means responsive to said contours causing said fingers to release said object and said spring means causing said fingers to reapply said grip to said object in at least one of said locations, whereby a function may be performed on said object at said one location without interference resulting from said grip on said object. 
     
     
       5. The automatic machine of  claim 4 , further comprising means for weighing said object by positioning said object on a scale while said grip is released and before said grip is reapplied, whereby a net weight of a product associated with said object may be confirmed for each object that is carried through said machine by said mandrel. 
     
     
       6. An automatic packaging machine comprising a conveyor for moving a plurality of object carrying mandrels around a closed path, a cam track accompanying said path, said cam track having contours which define functional locations along said path, each of said mandrels having a plurality of fingers which move variable distances together or apart in order to grip or release one of a plurality of objects having different widths, means responsive to said contours of said cam track for causing said fingers to release said object, spring means for causing said fingers to grip said object, whereby objects of different widths are selectively carried by said mandrels without requiring a readjustment of said machine, wherein said mandrels further include a support plate having at least two pairs of elongated slots, said pairs of elongated slots being oppositely disposed, said elongated tracks of each pair being vertically aligned, each finger being movable in an associated elongated slot, means including a spring for pulling said fingers toward a center of said support plate in order to grip said object, and means responsive to a cam follower for moving said fingers away from the center of said support plate to release said grip in response to said contours of said cam track. 
     
     
       7. An automatic packaging machine comprising a pair of conveyor chains forming a closed path through said machine, a cam track extending between said conveyor chains and along said closed path, said cam track having contours which define work station locations on said path through said machine, a cam follower for following said cam track, a plurality of mandrels carried by said pair of conveyor chains and controlled by said cam follower, each of said mandrels having a plurality of replaceable fingers for gripping and releasing an object, means including a spring for pulling said fingers to grip said object, and means responsive to said cam follower and said contours of said cam track for enabling said spring means to apply said grip and for overcoming said spring means for opening said fingers and releasing said grip on said object, wherein each of said fingers has a circumferential groove for supporting a blank for a non-parallelepiped box, said spring means pulling said fingers for opening said non-parallelepiped box. 
     
     
       8. A mandrel for use in an automatic packaging machine, the automatic packaging machine including a conveyor having a cam track, the cam track having contours, the mandrel comprising: 
       a support plate defining two pairs of elongated slots, the pairs being oppositely disposed, said elongated slots of each pair being vertically aligned;  
       a finger movably supported in each of said elongated slots;  
       a cam follower supported to travel in the cam track and along the contours, said cam follower being guided by the contours as a function of an instantaneous position of said mandrel as said mandrel travels along the conveyor; and  
       a spring operable to close said fingers to grip an object between said fingers, movement of said cam follower along the contours of the cam track overcoming a force of said spring to open said fingers.  
     
     
       9. The mandrel of  claim 8 , wherein said fingers grip the object at any position along said elongated slots responsive to the spring being enabled by said cam follower traveling in the cam track. 
     
     
       10. The mandrel of  claim 8 , wherein each finger defines a circumferential groove to grip and squeeze opposite edges of a blank to form the object. 
     
     
       11. The mandrel of  claim 10 , wherein the object is an oddly shaped box, and wherein said fingers grip and squeeze opposite edges of the blank to form the oddly shaped box. 
     
     
       12. The mandrel of  claim 11  wherein the oddly shaped box is a barrel-shaped box, and wherein said fingers grip and squeeze opposite edges of the blank to form the barrel-shaped box.